Nixie Clock I
Built from a dead frequency counter. The tubes and power supply worked fine. so I built a clock circuit and spliced it in.

The colons are orange LEDs stuck behind the tubes. The AM/PM light is also an LED, and the "tens of hours" digit is an NE-2 neon bulb.

Uses an ATmega48, a DS1307 real-time clock, a DS32kHz temperature-compensated crystal oscillator, and a lithium backup battery.
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